1. FIELD OF THE INVENTION
The present invention relates to a variable frequency dividing circuit adapted to receive a signal from various types of signal sources operating in different frequency zones or ranges and provide a frequency divided output to synchronize various signal-receiving units such as a car clock, flashers, intermittently operated wipers or the like in which circuit the frequency dividing ratio is electrically controlled.
2. DESCRIPTION OF THE PRIOR ART
In conventional frequency divider circuits, it has been a common practice to connect a frequency dividing circuit to a specific oscillating source and obtain various timing signals from the various stages of the frequency dividing circuit to synchronize various types of operating units such as a car clock, flasher, intermittently operated wipers and so forth with the aforesaid timing signals.
In these conventional frequency dividing circuits, the frequency dividing ratio has been kept fixed, and because timing pulses for the operating units are also specifically designated, the result is that the frequency of the oscillating source must also be specified. Consequently, the aforementioned frequency dividing circuit is not readily adapted to oscillating sources of similar or different type operating in different frequency or ranges. Also, since most frequency divider circuits are fabricated as integrated circuits having a limited number of output pins it is difficult to alter the frequency dividing ratio by changing the connections of the output pins. As a result, it has been necessary to specifically design the frequency dividing circuits for corresponding oscillating sources and with the resultant disadvantage that production efficiency and maintenance efficiency are reduced because full standardization cannot be achieved.